Gibraltar is an odd choice given that its status is covered by the Treaty of Utrecht (1714), and there hasn't been a military conflict since the 18th Century which rather predates the modern OG.
All British overseas territories have the right to self-determination if they want it. Gibraltar is the exception as it must be offered to Spain rather than granted independence under the terms of the Treaty. Nevertheless, it is up to the Gibraltarians whose descent is from a mixture of Andalusian Spanish (the largest group), Genoese Italian, Maltese, North African Jews, South Asians and British where their future lies.